I have a digital cable box that has a great picture. However, I notice that channels 101, 102, 105 and 107 drop out almost all of the time. All of the other channels work perfectly. I have it split 2 ways at this spot. When I took off the splitter, all channels worked and looked great. I assume that an amplifier will help. So...Will any Radio Shack amplifier will work with a Scientific Atlanta 3100 cable box? What one would you suggest

Sabre, first of all, you have the splitter after the cable box, right? Just making certain. I'd guess the cable company would tell you that the box won't put out a signal strong enough to be split, so you'll "need" a second box. However, I've never seen a box that couldn't have its output split at least once.

The output of the box would be on channel 3 or 4, and not change as you switch channels, so the tuned-in cable channel shouldn't affect the signal strength. You should have plenty of signal, or weak signal, accross all of the channels. The signal strength should depend on the output of the RF modulator at the box output.

To answer your question, an RF booster (amp) shouldn't help, meaning that it shouldn't be necessary, but if it does help, there might be something wrong with the box. Again, the same boost should be needed accross all channels, or none.

The only thing that makes sense to me is that for some reason, only digital channels are affecting the output strength, but why only on some channels? Are the channel numbers you mentioned the only high numbers you get, or are they the only ones that drop out?

Last thought: try swapping the output channel from 3 to 4, or 4 to 3, see if that makes any difference. Otherwise, ask the cable company to let you try another box. It makes no sense that you'd go from great signal to dropping out, and nothing between. "Dropping out" is a digital phenomenon; analog usually weakens 'smoothly'.

Larry
www.fineelectricco.com

Thanks for the help Larry. Let me see if I can explain further. The cable coming into the house is split 3 ways. Basement, Kid's Bedroom (Internet), and Family Room. I then have a split at the Family Room...one to the family room and one to the master bedroom. I am using S-Video out of the Cable Box to the TV so I am using the Video 1 input so the channel # wouldn't matter. All of my analog channels look great. I get about 35 of the standard digital channels, and all (but the 4 that I mentioned) are working. Does that help any?

This message was edited by sabrenut on 02/04/02 11:38.18.

Let's see....

Something like this?:



Now, refer back to your initial post, and tell me which splitter you remove (the 2-way, right?), which TV doing so helps, one or both of those being split, etc. Do the same channels have the same problem on all sets?

Also, does doing the same thing with the 3-way splitter help, too? And, there's no problem with the cable modem going through a splitter? Let's narrow this down.

Larry
www.fineelectricco.com

This message was edited by Larry Fine on 02/04/02 22:42.11.

Try using a new splitter that will pass 1000 MHz or better yet 1GHz (more than you need) this should solve your problem. If you need an amplifier use a two way amp generaly 54-1000 MHz forward path w/ 5-42MHz return path (needed for your digital box).

John

Larry-

You have diagrammed it perfectly. I only have the Digital Cable Box in the family room, but all analog channels are good throughout the house. I didn't even think to try the Cable Box on the TV in the basement.
I'll try moving the cable box around and see how I make out. I'll keep you posted. Thanks again!

Okay. From all of the info, I would now say that the problem is that the number of splitters is the problem. A single 4-way splitter would introduce less loss than a 3-way cascaded with a 2-way, even though you would have to run another coax to the 3-way location from the 2-way location. Thus:



The single splitter will definitely result in a stronger signal to the digital box, and now that I know you have the splitters before the digital box, dropp-outs is exactly the right term.

Oh, by the way, to John W.

1000MHz and 1GHz are the same thing.

Larry
www.fineelectricco.com

Larry-

I used a similar principle to solve it. Off the 2-way split in the family room I was sending the cable to the VCR first and the from the VCR out to the cable box. I replaced the 2-way with a 3 way, and I sent the strongest signal out to the cable box and the other 2 outs to the VCR and master bedroom. PROBLEM SOLVED!!!

Thank you very much for your help!!!

You're very welcome. That's why we're here!

Larry
www.fineelectricco.com